Miniature orchid leaf loss

[shadowteme]

Hi guys,

does anyone have experience with miniature orchids, specifically Diplocaulobium Abbreviatum? I believe it's also called dendrobium abbreviatum if that helps.

I had this orchid for over a year now and it has been doing really well in this paludarium I built. The roots are going crazy growing every which way, it trippled in size at least, always growing new pseudobulbs that are big and plump and healthy looking (no flowers as of yet tho).

However, these past couple months it slowly started losing some leaves; they yellow from the tip and fall off in a couple days, some have darker, dried up looking spots. It was gradual enough at first and started with the oldest growths that I didn't pay it much attention, but now there are a lot of leafless bulbs and the newer ones are starting to yellow and fall...



As you can see the damage doesn't spread any further, the bulbs themselves are fine.

Conditions have been stable, temperature is around 20-25°C, humidity somewhere in the 75-85% range, I spay with rain water daily. There are no pests that I have seen apart from the occasional mini snail in the moss wall but never around this particular orchid and those tend to go for the root tips in my experience anyway, but no sign of that here.

Can anyone help?